WIRING

Power is supplied to the 691 Control Module at all times. To prevent unintended actuation of the 691 System, be sure the "lock" - "release" switch (if applicable) is in the "release" position.

Do not operate the 691 Power Unit without first filling the power unit reservoir with proper fluid.

691 Wiring Instructions

(Refer to diagrams on pages 14 & 15)

The 691 System is designed for use on vehicles with a 12 volt DC, negative ground system. References to "ground" in this literature refer to vehicle chassis ground which is connected to the negative (-) battery terminal. References to "hot" or "positive" refer to connection to the positive (+) terminal of the 12 volt DC battery.

NOTE

All positive connections to the battery must be made through a high quality, properly rated fuse. Do not use a slow blow fuse or circuit breaker.

Optional extension harness (32-820-022, page 19) is available from MICO, Incorporated when the control module is not mounted directly to the power unit. The supplied wire harness has been designed with sufficient wire length to complete most installations. If additional wire is necessary, be sure to use the proper gauge.

When making wire connections, soldering and sealing with adhesive lined heat shrink is the recommended method.

All wires that are not used must be sealed and insulated to keep from shorting to each other or ground.

Connecting External Inputs

Activating the 691 System by use of the user interface rocker switch is not always convenient. External inputs can activate the 691 System through the use of external switches, dash mounted switches or relays. This provides flexibility for manual operation by the user or allows other circuits to activate the brakes.

External Inputs

There are three external inputs available. The 691 is activated upon receiving a signal at any of the inputs and does not deactivate until all input signals have been removed.

Two of the external inputs are activated by a positive signal (+12 VDC) and the third is activated by a negative (ground) signal.

The negative input is accessed from the gray wire in the main 691 Wire Harness.

The two positive inputs are:

1. The green wire in the user interface cable.

2.The brown wire in the main 691 Wire Harness.

NOTE: These inputs are connected together internally, so if one is receiving a positive sig- nal, the other will also have a positive signal present. This is commonly used to provide an external signal (to the brown wire) when the switch on the 691 User Interface is activated.

To prevent unintentional activation of the 691 System, insulate and seal any of the unused wires.

Using the Brown Wire as an External Output

When activating the 691 System with the user interface, the brown wire can be used to signal other circuits. It will provide a positive signal up to 1 amp of power to lights, relays, etc. If this current limit is exceeded, the output or control module may operate erratically or not at all.

*NOTE: The brown wire will not provide an output when the 691 System is activated by the external input of the gray wire. This is an inherent design to provide protection from improper wiring.

If the gray wire is allowed to short to ground, the vehicle brakes will apply.

Connecting the Vehicle Horn

The yellow 691 harness wire must be connected to a horn or other suitable warning device for your application. The yellow wire sends a ground signal to sound the horn when necessary.

1.On most vehicles the best way to connect this wire without adding a relay is to find the horn wire from the horn switch in the steering wheel. This switch typically grounds this wire to sound the horn, splic- ing in the yellow wire at this point is all that is necessary.

2.If splicing into the horn switch wire is not convenient, add a relay that is switched by the ground signal from the yellow wire and that connects the appropriate signal directly to the horn itself.

The yellow wire will provide a ground of up to 1 amp to drive a warning device. If this current limit is exceeded or if the yellow wire is connected improper- ly, the warning device or control module may operate erratically or not at all. Be sure to check for proper operation of the horn circuit on a regular basis. See page 11, "HORN WARNING CIRCUIT TEST".

Connecting Power for the Control Module

1.Connect the black wire directly to battery negative or equivalent ground. This wire carries the full current of the 691 System and must have a good ground. If additional wire is necessary for this connection it must be a minimum of 14 gauge wire.

2.Connect the red wire to a 30 amp fuse which is connected directly to battery positive. This wire also carries full 691 System current. Do not connect this through any auxiliary wiring. Do not use a slow blow fuse or circuit breaker.

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